Question

1. A metal sphere with a surface area of half a meter squared is charged from neutral to to 96 mC/m² at a constant rate 8 mA. How many seconds does this take and how many electrons per second are transferred? Use 16x10^-20 C for the charge of the electron.

2. Suppose an alkaline 9 V battery can supply 100 mA (to power a small light bulb, for example) for about 4 hours before too much of the voltage is depleted to be of use. It is therefore described as having a capacity of 400 mAh (milliamp-hours). How many electrons is this? Use the same charge for the electron as before. Also, where do the electrons come from and where do they go?

Answer 1